Summary: DETECTOR UPGRADE STUDIES ON COMPACT MUON SOLENOID HADRONIC ENDCAP CALORIMETER FOR SUPERLHC
F. Duru, U. Akgun, E. A. Albayrak, A. S. Ayan, P. Bruecken, J. Olson, Y. Onel
The University of Iowa
INTRODUCTION
The Large Hadron Collider (LHC) is designed to provide 14 TeV center of mass energy with proton proton colli-
sions every 25 ns. After a few years of run, the conditions of LHC will be upgraded to operate at 10 times higher
luminosity (L=1035 cm-2 s-1) allowing new physics discoveries. This period is called SuperLHC (SLHC). In the
current design, CSM Hadronic Endcap (HE) calorimeter uses Kuraray SCSN81 scintillator tiles, and Kuraray Y-
11 double clad wavelength shifting (WLS) fibers. It has been shown that these materials are moderately radiation
hard up to 2.5 MRad of radiation. The scintillation photons are collected by wavelength shifting fibers which have
the geometry shown in Figure 1.
BENCH TESTS:
In University of Iowa - CMS Laboratories, all quartz fiber geometries were tested for surface light collection
non-uniformities using UV-LED (380nm), Nitrogen Laser (337nm), and Mercury lamp (365 nm and 404 nm) as
the light sources. Instead of using the charged particles from a radioactive source we used light source itself and
imitated the Cerenkov radiation by giving the light to a specific location on the plate. Light was carried from the
source to the plate with a quartz fiber. For this purpose one side of the plates was not wrapped. Computer con-
trolled X-Y scanner was used to scan the surface of the plates with 0.4 mm steps. Figure 10 shows the setup.
3) "BIGGER" QUARTZ PLATES
We tested 6 Polymicro solarization quartz plates with dimensions of 20 cm x 20 cm x 6 mm using 120 GeV and 64